1. Field of the Invention
The present invention relates to a MEMS device chip manufacturing method.
2. Description of the Related Art
In a manufacturing process for a MEMS (Micro Electro Mechanical Systems) device such as an acceleration sensor, pressure sensor, and microphone, a plurality of MEMS devices are formed on a silicon wafer. Thereafter, the silicon wafer is divided along division lines to manufacture individual MEMS device chips. In forming the MEMS devices, the silicon wafer is subjected to photolithography and etching to thereby form a large amount of MEMS devices such as diaphragms for pressure sensors, cantilevers for acceleration sensors, and back chambers for microphones as disclosed in Japanese Patent Laid-Open No. Hei 7-240395, for example. The strength of the wafer processed by etching is reduced. Accordingly, the wafer is conventionally etched in the condition where each MEMS device has a thickness larger than necessary in order to prevent damage to the wafer in handling.